Jeff Liebermann wrote in message
i8hgablmsjqedh09sag3mvsh9g632ggf5d@4ax.com:

That said this:
"They're called rainbow tables because each column has a
different reduction function and sortof looks like a rainbow."

I found, after lots of bad hits, a few similar hints here:
https://stackoverflow.com/questions/5051608/rainbow-table
"they call it Rainbow tables because they use a different
reduction function on each column on the table"

And another hint here:
http://kestas.kuliukas.com/RainbowTables/
"Rainbow tables differ in that they don't use multiple tables
with different reduction functions, they only use one table.
However in Rainbow Tables a different reduction function is
used for each column."

I forgot to put the cite where this supposedly came from
https://books.google.co.uk/books?id=lWtuAAAAQBAJ&pg=PA127&lpg=PA127&dq=why+are+they+called+rainbow+tables&source=bl&ots=elqt2z_ByD&sig=pmoJ4oRmLHlKjmtEQTifD2ESZ6U&hl=en&sa=X&ved=0ahUKEwjs49Ly9sjKAhWGaxQKHZ2WD_IQ6AEIYDAL#v=onepage&q=why%20are%20they%20called%20rainbow%20tables&f=false

Richard Kettlewell wrote in message 877fiv10m2.fsf@mantic.terraraq.uk:

Some said the term was coined in "Making a Faster Cryptanalytic Time-Memory
Trade-Off" by Philippe Oechslin (2003) in which he describes an
improvement to Hellman's method. He doesn't explain the term.